Engine



A. E. PETERS ,756

ENGINE Filed Spt. 2'7, 1923 3 Sheets-Sheet l INVENTOR Hus ATTOR EY Hui/1 uvEPe-fevd.

Sept. 22, 1925 1,554,756

A. E. PETERS ENGINE Filed Sept. 2'7, 1923 3 Sheets-Sheet 2 BY I I (Z 'ms ATTO Ev v Sept. 22, 192 5. w

h A. E. PETERS ENGINE Filed Sept. 27. 1923 s Sheets-sheet s Q\ Y N ms ATfo NEVY Patented Sept. 22, 1925.

UNITED STATES- PATENT OFFICE.

ARTHUR E. PETERS, 01 LITTLETON, COLORADO, ASSIGNOR TO INGERSOLIl-RAND COM- PANY, F JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

ENGINE.

Application filed September 2'7, 1923. Serial No. 665,234.

To all whom it may concern:

Be it known that I, ARTHUR E. Pn'rnns, a citizen of the United States, and a resident of Littleton, county of Arapahoe, and State v 5 ,of Colorado, have invented certain Improve- ,Inents in Engines, of which the following is a specification accompanied by drawings.

This invention relates to engines of the square piston type, actuated by a motive fluid under pressure and more particularly to that type of engine in which there are provided a plurality of pistons, reciprocatory one within the other, all acting to produce rotation of a common crank shaft.

The features of the invention hereinafter described are of general application but are of special advantage when applied to engines actuated by compressible fluid, as for instance compressed air. Square piston engines have heretofore been wasteful and ineflicient, partly because they have been constructed so as to utilize practically none of the expansible power of the air, and partly because of the peculiar arrangement of ad mission and exhaust ports. Ordinarily cer tain of the ports are located in one of the power pistons and describe a circular course 1 during which they come into registry with suitable admission and exhaust ports in the cover or cylinder head. This arrangement has supposedly made necessary a compromise between the size of the ports and the point of cutolf,that is to say, the larger the ports were made, the less cutoff effect was thought possible, and the smaller the ports, the greater the back pressure at exhaust. The chief loss in efficiency has been found to be due to the exhaust back pressure. Back pressure in engines of the type referred to is also caused by friction in the long and restricted passages for conducting the. exhaust fluid from the piston faces to the ports. These passages are also used on the power stroke to conduct the motive fluid into the cylinders but are not so objectionable for this purpose for the reason that fluid is being supplied at a relatively great pressure, whereas the exhausted fluid must be pumped out, as it were, and the power so employed, detracts from the power delivered by the engine. It is accordingly one of the objects of this invention, to secure a free exhaust of the motive fluid from the cylinders and at the same time to permit the use of an. early cutoff.

Other objects and advantages of the invention will be in part obvious and in part pointed out hereinafter. I i

The invention accordingly consists of an engine having novel features of construction, combinations of elements, and arrangements of parts which will be exemplified in the construction hereinafter set forth and the scope of the application of which will be 7 indicated in the appended claims.

In the drawings, forming part of the specification and in which similar reference characters refer to similar parts,

Figure 1 is a longitudinal sectional elevation on the line 11 of Figure 2 looking in the direction of the arrows illustrating one form of an engine constructed in accordance with the practice of the invention and shows the arrangement of pistons within the cylinders and the various ports for the admission and exhaust of motive fluid;

Figure 2 is a transverse section on the line 22 of Figure 1 looking in the direction of the arrows; and

Figures 3, l, 5, 6, 7 and 8 are diagrammatic representations of the engine partly in longitudinal section showing the relative positions of the ports associated with one end of the cylinders at six successive important positions in a cycle or one revolution of the crank pin, and indicates the flow of motive fluid to and from that end of the cylinder. 7

Referring to the drawings, and more particularly to Figures 1 and 2, the engine includes a frame A formed integrally witha base B by means of which the engine may .be suitably mounted on a foundation, as indicated at C. lVithin the frame A there is an accurately dimensioned main cylinder D preferably rectangular in cross section within which there is provided a reciprocatory frame piston E having an inner rectangular opening F the axis of which is at an angle to the axis of the main cylinder D, as for instance, at right angles thereto.

l Vithin the frame piston E, an inner piston G is arranged to reciprocate in a direction transverse to the direction of the motion of the frame piston E. The cylinder D is provided with covers or heads H and J which form the side walls. A suitable crank shaft K, journalled in the head H is provided with a crank disc L having a crank pin O journalled the inner piston G.

\Vhen the frame piston E and the inner piston G reciprocate in their respective cyhn would be the exhaust port, but in the present transmission of power from the shaft K,

a suitable pulley may be provided as at P.

In the head J which forms the front cover for the main cylinder D and the bore of the frame piston E, there are provided a plurality of ports for admitting motive fluid to the cylinders and exhaustingit therefrom. At the center of the head J there is a central port Q, in this instance the admission port, leading through a suitable boss R on the cylinder head for theattachment to a pipe or. other fluid conductor.

Disposed symmetrically about the central admission port Q, there are a plurality of outer exhaust ports S, T, U and V, which communicate with a common exhaust passage IV in the cylinder head J leading through a passage IV in the boss R to a suitable opening for connection to an exhaust pipe. It is understood that the outer ports S, T, U and V could be employed as admission ports if the motor was intended to be reversible, in which case, the port Q instance the motor is designed as a non-re versible engine so that the maximum efliciency may be obtained in one direction regardless of the reduced efliciency which might be obtained in the opposite direction of rotation. In order to transmit or distribute the motive fluid from the central port Q to the ends or faces of the pistons E and G, there are provided a plurality of ports in the inner piston G, arranged toregister selectively with the said admission and exhaust ports in the head and communicating by means of passageways with the faces of the pistons. To this end, there are provided four ports, X, Y, Z and a which are symmetrically located with respect to the center of the crank pin 0, so that when the crank pin rotates and the pistons E and Gr are moved therewith, the ports in the inner piston come into registry with the admissionand exhaust ports progressively, that is to say, one of the ports X,Y, Z and a will first register with the central or admission port Q, and thereafter pass by the latter port and come into registry with one of the outerv exhaust ports S, T, U and V in the cylinder head toopen the face of the piston head to exhaust.

The distributing ports X, Y, Z and a communicate by means of the passages 19, 0, (land 6 with the respectiveend faces of the frame and inner pistons E and .G. As shown in Figure 1, the passages b and do not lead directly to the end faces of the frame piston E, but communicate therewith through apertures 0 and p. Because of the positioning of the distributing ports X, Y,

Z and a, the passages b, 0, d and e are constricted at certain points at which they pass by each other and this is unavoidable since thereis not sufficient room in the body of the inner piston to provide an unrestricted path for themotive fluid from the ports to the ends of the cylinders. This restriction tends to produce back pressure in the exhaust, for the passages are long and have bends at which they are reduced in cross section. To provide additional port area and a lessobstructed passage there are provided supplementary exhaust ports which in this particular construction are shown as exhaust ports arranged to cooperate or register with certain ofthe outer exhaust ports of the cylinder head. These supplementary ports indicated at 7, g, 71. and lead directly into the passages b, 0, (Z and e by which they are connected with the distributing ports X, Y, Z and a and arelocated at points close to the end faces of the, pistons, from which they are to exhaust the motive fluid.

The supplementary ports open into the outer or exhaust ports in the cylinder head at substantially the same time as the distributing ports X, Y, Z and a, respectively. At such times as the latter are communicating with the central port Q, the supplementary ports are blanked by the cylinder head J. All ofthe ports are shaped or outlined so that they open or register with each other on a line forming what is commonly known as a line opening, which is the least productive of wire drawing. In the operation of the engine the exhaust of motive fluid from each of the end faces of the pistons is facilitated by the use of two ports in the inner piston which register with the outer ports in the cylindervhead causing a free and comparatively unobstructed passage to atmosphere,

Referring to Figures i-B, 4, 5, 6, 7, and 8, there are shown various positions which the ports assume with respect to each other in the course of a cycle completed by a single rotation of the crank pin 0, only the ports which have to do with the admission or exhaust of motive fluid through the left hand face of the frame piston E being shown. All of the remaining ports are omitted from the drawing for the sake of clearness, it being understood that each set of ports operates inan entirely similar manner.

In Figure 3, the frame piston E is shown at the extreme limit of its stroke to the left, and the port X has just started to register with the admission port Q and motive fluidris just entering the space beyond the face of the piston E through the passages Z) and 0. At this position the exhaust ports S and T are at substantial distances from the distributing port Xand the supplementary port 7 respectively,

F ignre 4: shows the piston E continuing its hit) stroke toward the right, and the port X is widely openbut not fully open with respect to the admission port Q, the exhaust ports S and T remaining closed in this position.

Figure 5 shows the piston Eat the cutofii point. The distributing port X is about to be closed and as the exhaust ports S and T are still blanked by the cylinder head, an

opportunityisafforded for the expansion of motive fluid-in the cylinder for the remaining length of the stroke of the piston, which amounts in this instance to substantially 257 i i p In Figure 6, the frame piston E has reached the end of the stroke at the right and is ready to return, the exhaust ports S and T are beginning to register with the distributing port X and the supplementary port 7, respectively, and the motive fluid is being exhausted through the ports f and X, the major'part of it passing through theport f for the reason that this is the .most direct route to the-atmosphere. p

In Figure the piston E is shown. still moving'toward the left and the ports X and f are still in registrywith the exhaust ports S and T respectively. It will be noted that the distributing port X remains in communication with the port S for a longer period than the port 7 remains open to the port T, thus preventing any greatamount of compression. This does; not interfere with the exhausting of the spent fluicl,'since the greater part of such fluid has been exhausted almost instantaneously through the direct opening to atmosphere previously afforded by the supplementary port.

Figure 8 shows the relative positions of the distributing and supplementary ports with respect to the exhaust ports. This position substantially completes the cycle of positions through which the ports, associated with any one piston face, pass.

In the arrangement of ports described, the free exhausting of the spentfiuid'is expedited by the provision of supple mentary ports leadingdirectly to the cylinder vhead passageways without obstruction by devious and constricted paths. This eliminates to a large degree the loss of efficiency due to back pressure at exhaust.

Thus by the above construction, are ac; complished among others, the object hereinbefore' referred to. y

As many changes could bemade' in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. 7 I

It isalsoto be understood that the language used in the following claims is intended to cover all of the generic and specific features of the invention herein "described and all statements of the scope of the invention, which asa matter of language might be said to fall therebetween. n

I claim: A I

1. An engine comprising in combination amain cylinder having heads, a frame'piston within said main cylinder andprovided with an opening having its axis at an angle to the axis ofthe main cylinder, an inner piston in said frame piston opening, a central admission port in one of said headsQa plurality of outer exhaust ports in said head disposed symmetrically about said central admission port and communicating with a common exhaust passage in said head, and a plurality of ports in said inner piston arrange'd to register selectively with the'ports in said head and communicatingwith the end faces of said pistons, two of the said ports in the inner piston being connected with one end face of said piston whereby two of the said outerexhaust ports in said head are simultaneously placed in communication through two of said piston ports with a single end face of one of said pistons during the cycle of operation and only one of said two ports in the inner piston registers with the central inlet port. v

2. An engine comprising in combination a main cylinder having heads, a frame piston within said main cylinder and provided with an opening having its axis at an angle to the axis ofthe main cylinder, an inner piston in said frame piston opening, a central admission port in one of said heads, a

plurality of outer exclusively exhaust ports in said headdis posed symmetrically about said central admission port and communieating with a common exhaust passage in said head, a plurality of distributing ports in said inner piston arranged to register selectively with the admission and exhaust ports in said head and communicating with the end faces of said pistons, and supplementary exhaust ports in said inner piston connected with the distributing ports also communicating with the 'end faces of the said pistons andadapted to register selectively with the outer ports in said cylinder head. I

a main cylinder having heads, a frame piston within said main cylinder and provided with an opening having its axis at an angle to the axis ofthe main cylinder, an inner piston in said frame piston openin a cen- Ill) 3. An engine comprising in combination,

li-JU lectively with the'portsin said head communicating with the end faces of said pistons and supplementary exhaust ports connected with the distributing ports in said inner piston also communicating with the endv faces of said pistons and also adapted to register selectively with the outer ports insaid cylinder head, said. supplementary ports being adjacent to the end facesyof said pistons. p H

4. An. engine comprising in combination, ainain cylinder having heads, a frame piston within said main cylinder provided with an opening having its axis at an angle to the axis of the main cylinder, an inner piston inrsaid frame'piston opening, a central admission port in one ofsaid heads, a plurality of outer exhaust admission ports arranged symmetrically about said. central port and communicating with a common exhaust passage in said head, a plurality of symmetrically disposed distributing ports in said. inner piston and arranged to make line openings as they register selectively opening having its axis at an angle to the axis of said main cylinder, a central port admission in one of said cylinder heads, a plurallty of outer exhaust ports symmetrically arranged about said central admission nicatingwith the end faces of said pistons,

and a plurality ofsupplementary exclusively exhaust ports in said inner cylinder arranged to register with said outer ports and make line openings therewith, said supplementary ports being adjacent the end faces of said pistons with which they communi cate and connected with the distributing ports.

(i/An engine comprising in combination, a main cylinder having heads, a piston in said main cylinder and provided with an opening having its axis at an angle to the axis of the main cylinder, a central admission port in one of said cylinder heads,- four outer exhaust ports arranged symmetrically about said central admission port and communicating with a common exhaust passage in said head, an inner piston in said frame piston opening, a plurality of distribut-ing ports in said inner piston symmetrically arranged and adapted to register selectively with the ports in said head, passagewaysv leading from the distributing ports in said inner piston to theend faces of said pistons, and supplementary exclusively exhaust ports in said inner piston adjacent the end faces of the pistons and, communicating with said passageways and said dis tributing ports, said supplementary ports being arranged to register with said outer ports in said cylinder head simultaneously with the corresponding ports in said inner piston.

7. An engine comprising. in combination, a main cylinder having heads, a frame piston in said main cylinder provided with an opening having its axis at an angle to the axis of the said main cylinder, a central admission port in one of said cylinder heads, four exhaust ports disposed symmetrically about said central admission port and communicating with a common exhaust. passage in'said cylinder head, an inner piston in said frame piston opening, four. distributing ports in said inner .piston arranged to registerselectively with said admission and exhaust ports in the head and communicating with the end faces of said pistons, and sup plementary exclusively exhaust ports in said inner piston, also communicating with the end faces of said pistons and arranged to register selectively with. said. exhaust ports in the head.

8. An engine comprising in combination, a main cylinder having heads, a frame piston in said main cylinder and provided with an opening having its axis at an angle to the axis of the said main cylinder, a central admission port in one of said cylinder heads, four exhaust .ports symmetrically disposed aboutsaid central admission port and coinmunicatingwith a commonexhaust passage in said cylinder head, an inner piston in said frame piston opening, four distributing ports in said inner piston arranged to register selectively with said admission and exhaust ports and communicating with the end faces of said pistons, and supplementary exclusively exhaust ports iii-said inner piston also communicating with the end faces of said pistons and arranged to register selectively with said exhaust port and simultaneously with the registry .of the corresponding distributing ports with exhaust ports.

9. An engine comprising in combination, a main cylinder having heads, a frame piston in said main cylinder and provided with an opening, a central admission port in one of said cylinder heads, four. exhaust ports symmetrically disposed about said central admission port and communicating with a common exhaust passage in said cylinder head, an inner piston'in said frame piston opening, four distributing ports in said inner piston arranged to register selectively With said admission and exhaust ports and communicating with the .end faces of said pistons, and supplementary exclusively exhaust ports in said inner piston also -communicating with the end faces of said pistons and arranged to register selectively with said exhaust port, said supplementary ports being relatively close to the end faces of said piston.

10. An engine comprising in combination, a main cylinder having heads, a frame piston in said main cylinder provided with an opening having its axis at an angle to the axis of the said outer cylinder, a central admission port in one of said cylinder heads, four exhaust ports symmetrically disposed about said central admission port and communicating with a common exhaust passage in said cylinder head, an inner piston in said frame piston opening, four distributing ports in said inner piston arranged to register selectively with said admission and exhaust ports and communicating with the end faces of said pistons and supplementary exclusively exhaust ports in said inner piston also communicating with the end faces of said pistons and arranged to register selectively with said exhaust ports, said supplementary ports being relatively close to the end faces of said pistons, all of the said ports being outlined to form line openings with the ports with which they register.

In testimony whereof I have signed this specification.

ARTHUR E. PETERS. 

